Me too. In ISO testing, oil filters definitely decreased in efficiency over time. I'm betting, however, that there is more to the story than LSJR has decided all on his own that "ISO 4548-12 is wrong". And that's nothing personal against anyone here who considers it settled science. But, if he's wrong, he's wrong. I don't have any stake in it either way.I’m data driven. Show me the money
LSJr Take on Oil Filter Efficiency Improving with Loading
- Thread starter garageman402
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I see no reason why an oil filter that's loaded up with debris in actual use, even though it's a much slower loading rate, wouldn't also lose efficiency from loading. Debris loading is debris loading, regardless of the rate it occurs at. The filter media either catches the debris and holds it (doesn't shed the debris down stream), or not. I see no real impact of the rate of loading on that performance aspect of an oil filter. If there was any real impact, I would think that ISO 4548-12 would have been changed to account for that, but that ISO standard has been used around the whole world for over 25 years.
What could impact the ISO efficiency results is the flow rate going through the filter under test, but that flow rate is much lower than most engines can put out from the PD oil pump. So in real use, with engine RPM pretty high and a resulting much higher oil flow rate, the filter could actually lose even more efficiency for a short time under those much higher flow conditions. There are many factors going on with an oil filter mounted to engine, but the ISO test is done under constant conditions so the resulting lose of efficiency seen is real, and there's no good reason that the efficiency wouldn't also drop in real use as the filter loads with debris.
Granted, most people don't leave oil filters on long enough to allow such high loading. But some do of course, thinking that the filter "gets more efficient with loading", when in fact it's losing efficiency and allowing more debris to continually shed off the media and go into the oiling system - especially when they use a low efficiency filter for multiple uses or very lone OCIs.
The flow through the filter on a real engine could also be much higher at times than the flow rate used on the ISO efficiency test, which could make the filter shed even more debris in those use conditions. There is an ISO test to measure how bad a filter sheds debris from changing flow rates and the resulting dynamic dP across the media. That can also happen in an engine when the RPM and oil flow rate out of the pump is dynamic due to varying engine RPM.
What could impact the ISO efficiency results is the flow rate going through the filter under test, but that flow rate is much lower than most engines can put out from the PD oil pump. So in real use, with engine RPM pretty high and a resulting much higher oil flow rate, the filter could actually lose even more efficiency for a short time under those much higher flow conditions. There are many factors going on with an oil filter mounted to engine, but the ISO test is done under constant conditions so the resulting lose of efficiency seen is real, and there's no good reason that the efficiency wouldn't also drop in real use as the filter loads with debris.
Granted, most people don't leave oil filters on long enough to allow such high loading. But some do of course, thinking that the filter "gets more efficient with loading", when in fact it's losing efficiency and allowing more debris to continually shed off the media and go into the oiling system - especially when they use a low efficiency filter for multiple uses or very lone OCIs.
The flow through the filter on a real engine could also be much higher at times than the flow rate used on the ISO efficiency test, which could make the filter shed even more debris in those use conditions. There is an ISO test to measure how bad a filter sheds debris from changing flow rates and the resulting dynamic dP across the media. That can also happen in an engine when the RPM and oil flow rate out of the pump is dynamic due to varying engine RPM.
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All great points!
I agree, although I’ve been doing it for 20 years without ill affects. Yet oil filter particle loading seems to be more deleterious than air filter loading.
Serious question: is there truth to air filters increasing in efficiency with dirt accumulation, and if so, why would an oil filter be different? No doubt, with debris accumulation, pressure across the filter will increase, which would be a negative. But what everyone is worried about is particle collection.
Of course lack of good air filtration can do more damage, and some of that ingested debris can also work its way into the oil. Both air and oil filtration is important. The only thing left to remove debris in the oil is the oil filter, or an oil change. The bottom line concluded by every engine wear study is that cleaner oil does result in less wear, regardless of how small or large the wear difference is. If someone doesn't think the oil filter matters, then that's their decision for their vehicle ... not mine, lol.
If there was only 10 to 20 in-H20 of dP across an oil filter it might also increase efficiency with loading ... but the dP and flow force (oil is much higher viscosity than air) going through the media is magnitudes higher. Put enough air flow through an air filter and I bet it would start shedding already captured debris too.
Here's a way to prove if an oil filter with debris loading at a slow rate in real use changes its efficiency.
1) Find a beater "test car" with pretty dirty engine internals. Engine has to take a spin-on oil filter.
2) Chose an oil filter that isn't real efficient that fits the engine, and has a pretty high bypass valve setting.
3) Have that specific oil filter ISO 4548-12 tested, but only with just enough debris loading to get a "new" efficiency baseline.
- This is where LRJr could do a test like this because he has connections, like at Donaldson who can do ISO testing for him, for free I bet.
4) Put that same oil filter on the beater test car.
5) Run some Valvoline Restore and Protect to get some increased debris loading on the filter. Do at lease a 5K run. Hire someone to put those miles on in a relatively short time so not waiting for a year for test results. Or find someone with a beater test car to volunteer.
6) Remove that filter and send it back to the same ISO test lab for more efficiency testing after it's been loaded in real use.
7) Does the ISO efficiency test data show the filter is less efficient after being loaded up in real use.
PS - Or after step 4), you could instead find a beater car (that you don't care about) where you can add the ISO test dust at low levels to load up the filter pretty good, but slowly over a 5K+ OCI. Or get a beater engine and put it on a test stand in the lab and run this test with ISO test dust added slowly over a simulated 5K+ OCI, to essentially load the oil filter to at least half of its capacity to see if it "gets more efficient" with increased loading. I doubt it will, I think you will see an efficiency decrease just like in the ISO 4548-12 testing.
Might be a good LSJr YT video ... you reading this Lake? I get a cut though for the test planning.
1) Find a beater "test car" with pretty dirty engine internals. Engine has to take a spin-on oil filter.
2) Chose an oil filter that isn't real efficient that fits the engine, and has a pretty high bypass valve setting.
3) Have that specific oil filter ISO 4548-12 tested, but only with just enough debris loading to get a "new" efficiency baseline.
- This is where LRJr could do a test like this because he has connections, like at Donaldson who can do ISO testing for him, for free I bet.
4) Put that same oil filter on the beater test car.
5) Run some Valvoline Restore and Protect to get some increased debris loading on the filter. Do at lease a 5K run. Hire someone to put those miles on in a relatively short time so not waiting for a year for test results. Or find someone with a beater test car to volunteer.
6) Remove that filter and send it back to the same ISO test lab for more efficiency testing after it's been loaded in real use.
7) Does the ISO efficiency test data show the filter is less efficient after being loaded up in real use.
PS - Or after step 4), you could instead find a beater car (that you don't care about) where you can add the ISO test dust at low levels to load up the filter pretty good, but slowly over a 5K+ OCI. Or get a beater engine and put it on a test stand in the lab and run this test with ISO test dust added slowly over a simulated 5K+ OCI, to essentially load the oil filter to at least half of its capacity to see if it "gets more efficient" with increased loading. I doubt it will, I think you will see an efficiency decrease just like in the ISO 4548-12 testing.
Might be a good LSJr YT video ... you reading this Lake? I get a cut though for the test planning.
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4wd
$50 site donor 2026
Here's a way to prove if an oil filter with debris loading at a slow rate in real use changes its efficiency.
1) Find a beater "test car" with pretty dirty engine internals. Engine has to take a spin-on oil filter.
2) Chose an oil filter that isn't real efficient that fits the engine, and has a pretty high bypass valve setting.
3) Have that specific oil filter ISO 4548-12 tested, but only with just enough debris loading to get a "new" efficiency baseline.
- This is where LRJr could do a test like this because he has connections, like at Donaldson who can do ISO testing for him, for free I bet.
4) Put that same oil filter on the beater test car.
5) Run some Valvoline Restore and Protect to get some increased debris loading on the filter. Do at lease a 5K run. Hire someone to put those miles on in a relatively short time so not waiting for a year for test results. Or find someone with a beater test car to volunteer.
6) Remove that filter and send it back to the same ISO test lab for more efficiency testing after it's been loaded in real use.
7) Does the ISO efficiency test data show the filter is less efficient after being loaded up in real use.
PS - Or after step 4), you could instead find a beater car (that you don't care about) where you can add the ISO test dust at low levels to load up the filter pretty good, but slowly over a 5K+ OCI. Or get a beater engine and put it on a test stand in the lab and run this test with ISO test dust added slowly over a simulated 5K+ OCI, to essentially load the oil filter to at least half of its capacity to see if it "gets more efficient" with increased loading. I doubt it will, I think you will see an efficiency decrease just like in the ISO 4548-12 testing.
Might be a good LSJr YT video ... you reading this Lake? I get a cut though for the test planning.
Saw your comments. Some of the comments were clearly from BITOGers
I'll be interested to see if he answers regarding the testing questions raised here.
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Yep. Always lots of haters and people taking it beyond disagreement and making it personal with derogatory remarks and opinions.Saw your comments. Some of the comments were clearly from BITOGers
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Probably replace it every other OCI in a well kept engine.
It was over their head.Saw your comments. Some of the comments were clearly from BITOGers
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That would my response if someone made a video about US tax code and for some reason I watched it.
Ironic that the comment lacks brevity.Saw your comments. Some of the comments were clearly from BITOGers
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It’s not clear to me whether Lake misspoke about the increasing efficiency, or simply forgot to add a caveat.
Also, it seems to me with LSJr ‘s personal and professional experience, that practically any information automotive wise would be a phone call away for him.
Per the issue I believe both sides are correct, as is usually the case on Bitog.
Also, it seems to me with LSJr ‘s personal and professional experience, that practically any information automotive wise would be a phone call away for him.
Per the issue I believe both sides are correct, as is usually the case on Bitog.
I don't know anything with certainty; I wasn't there and I haven't spoken to LSJR or anyone from Donaldson, but I'm betting that a guy who calls himself "The Motor Oil Geek" didn't just talk about air filters on his visit with the filtration experts. Nor do I think he would misconstrue or misunderstand something as simple as "The same principle that applies to air filters, applies to oil filters; they increase in efficiency with loading, up to a point". Is LSJR a simple minded idiot? Does he not understand the testing and the science? Is he a bold faced liar? Is he intentionally misleading? He may well be wrong, but I don't think he's any of those other things. That's why I'm holding out to hear more detail and explanation from him (and maybe Donaldson). Maybe there is some kind of caveat we haven't heard. If so, the longer we go without hearing it, the more his credibility will be damaged.
4wd
$50 site donor 2026
Or it happens early on - but at some point in loading it starts going the other way …
If I buy a 20k filter - I’m done at 10k/12k …
Wonder what would the caveat be with respect to oil filters? I can't think of one except that he believes the ISO 4548-12 test isn't representative of how oil filters behave with increased loading. But then it's seems like LSJr doesn't really understand the ISO test spec to begin with based on some of his comments about it.
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